Belts closed in an endless manner represent closed annular elements which can be used for example as drive belts such as, for example, V-belts for power transmission. However, they can also be used as conveyor belts in order to transport loose bulk materials, for example. They can also be used as caterpillar tracks in tracked vehicles for moving the vehicle.
Belts of this type generally run around a drive and further guide or support rollers, in order for the drive power to be transmitted to a take-off element (V-belt), in order for the drive power to be utilized for transporting material (conveyor belt) or for a vehicle to be moved around (caterpillar track). To this end, these belts have a predetermined elasticity, which can be achieved for example by the use of an elastomeric material, for example rubber, as the base material of the belt. Moreover, these belts usually have one or more strength members in the longitudinal direction for transmitting the tensile forces in the running direction of the belt. The strength members can be, for example, steel cables which permit a particularly high force to be transmitted. However, woven textile fabrics are also commonplace as strength members.
Belts of this type can be produced, for example as V-belts, to some extent in an already closed manner. In most cases, for example as conveyor belts or caterpillar tracks, the belts are produced in a usually open manner, that is, as an elongate body, on account of their length in the longitudinal direction, and are also transported to the site of application in this state. They are then closed in an endless manner there. Closing in an endless manner can take place, for example, by the two ends being joined together by vulcanization, but this precludes a non-destructive separation of the ends and thus opening of the belt again, for example in the case of wear or damage. Furthermore, this requires a great deal of effort at the application site.
Therefore, it is known for the ends of the strength members to be left free of elastomeric material, or to be exposed, at the two ends of the open belt, and for these ends to be connected mechanically. This can take place, for example, in that the respective ends are clamped in a respective common coupling element and the two coupling elements are connected together, for example in a hinge-like manner, via a coupling bar. On account of this mechanical clamping connection being divided between two coupling elements which are then rotatable with respect to one another as a joint, the flexibility of the belt as a whole is intended to be limited as little as possible. This may be required in particular in the case of tight deflection radii.
U.S. Pat. No. 9,506,526 B2 shows a corresponding belt made of an elastomeric material having a strength member ply made of steel cables that extend in the longitudinal direction of the belt and are arranged parallel to one another. The steel cable ends are in each case clamped in a belt end body. The two belt end bodies are intercoupled in the manner of a hinge.
A belt that is closable in an endless manner, having at least one strength member that runs in the longitudinal direction of the belt and a common connection element which can interconnect the two strength member ends is known from DE 10 2014 224 526.5 (unpublished). The two strength member ends have in each case at least one holding element that is fastened in a force-fitting manner, the holding elements in the longitudinal direction being able to be held in a form-fitting manner by the connection element. To this end, the strength member ends can be press-fitted in the respective holding element and then be placed into a common receptacle space of the connection element. In this way, the holding elements can be held in a force-fitting manner at the strength member ends, and can be held in a form-fitting manner in the longitudinal direction, for example via crenelated protrusions of the connection element.
DE 10 2015 212 750.8 (unpublished) discloses a comparable mounting of the strength member ends, wherein the strength member ends here are in each case received in a form-fitting manner in separate connection elements via holding elements that are press-fitted thereon in a force-fitting manner. The two connection elements can interact in the manner of a hinge in order to establish the endless closure of the belt, as is the case in U.S. Pat. No. 9,506,526 B2.
It is disadvantageous herein that the strength member ends, on account of the latter being press-fitted, are usually deformed in the holding elements. This is caused by pressing forces which in the press-fitting of the holding elements act perpendicularly to the cross section of the strength members. The original circular cross section of the strength members within the holding element herein is usually deformed to an oval cross section. This oval cross section can continue outside the holding element. The oval deformation herein can decrease as the distance from the holding element in the longitudinal direction increases.
If the oval deformed region of the strength member which is outside the holding element is guided into a cylindrical opening such as, for example, a bore of the connection element which per se corresponds to the cylindrical cross section of the strength member, this can lead to a deflection of individual external strands of the strength member on the edges of the cylindrical openings. On account of this deflection, or of any buckling, respectively, of the oval strength member on the edges of the cylindrical opening, damage to or severing of the strands, respectively, can occur, on account of which the transmissible tensile force of the strength member can be reduced, the latter rupturing in the case of excessive tensile stresses.